Means for taking oil from wells



Dec. 26, 1939.

C. l.. A. TQDD MEANS FOR TAKING oIL FROM wELLs Filed oct'. 4, 19:55

2 Sheets-Sheet l SMC/wm .III

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IIIY-II Dec. 26, 1939. L A, TODD A v2,184,784

MEANS FOR TAKING OIL FROM WLLS Filed Oct. 4, 1935 2 Sheets-Sheet 2 sz ,A

ummm j/Qg? Patented Dec. 26, v1939 U I T il:

stars 4; ortica 9 Claims.

The present invention relates to means for taking oil from wells and particularly from wells in so-called water drive elds.

In water drive wells it has hitherto been the practice to pump out the oil and water in miXed condition and then to ei'ect separation. This practice is costly in view of the larger volume of liquid raised in proportion to recoverable content and in View also of the cost of recovery.

According to the present invention a separated condition of the oil and water is maintained and only oil is lifted so that, obviously, great economy in production is afforded.

In the usual procedure, a pump is disposed in the well a short distance below the natural level of the liquid column. As pumping proceeds, water is drawn as well as oil and the two are discharged in emulsied condition. Moreover, the disturbance of the underlying strata occasioned 1 by the pump suction results in obstructing the access of the oil to the well bottom.

In carrying out the present invention, intermingling of the water with the oil is prevented by maintaining a high bottom hole pressure by blocking the well adjacent its bottom, so that water is prevented from rising in the well. Since the usual oil well pump will not operate with a pressure at its inlet greater than that at its outlet, I provide pressure reducing means of suitable design between the bottom hole and vthe pump intake.

' By way of illustration, I have shown in the accompanying drawings three specic examples of pressure reducing means which may be employed in carrying out the new method. The first example comprises an isolation chamber into which oil introduced at the high pressure of the well bottom assumes substantially` atmospheric pressure and is withdrawn from the chamber, in.r r this low pressure condition, by the pump. The

second example comprises a reducing valve auto- `matically controlled in dependence upon the differential existing between bottom hole pressure and the 'static pressure of the column of oil in the tubing line above the pump. The third example comprises simply a manually adjustable y posed between the intake end of the pump and the bottom of the well. v

, cylindrical Aform and built up of sections, as par- (Cl. 10S-40) Figure 2 is an enlarged sectional view of that portion of Figure l embraced by bracket 2.

Figure 3 is an enlarged sectional View of that portion of Figure 1 embraced bythe bracket 3.

Figure l is an enlarged longitudinal ysection of that portion of Figure l embraced by bracket 4. Figure 5 is a section substantially on line 5--5 of Figure 4. A,

Figure 6 is a section substantially on line 6 6 of Figure 3.

Figure-'7 .is a longitudinal sectionv of a well casing and the appurtenances of the present invention, including in this instance a differentially controlled reducing valve. l

Figure 8 is an enlarged Sectional view of reducing valve of Figure 7, and

. Figure 9 is a view similar to that of Figure 8,

but showing a simple spring loaded reducing ticularly shown in Figure 3, the terminal sec- 2,5 tions having reducedextremities which are eX- ternally threaded. A pipe section 22 secured to the upper end of chamber 2| by means o f a coupling 23 passes into and is supportedv by a packer 2t of any suitable design. Section 22 communicates through the packer' with a pipe section 25 screwed in the upper end of the packer and provided with an opening 25 in the casing n interior. A coupling 26 secures section 25 to a double ended hollow plug 2l whose upper end is screwed into the lower end of a pump barrelz, the lower end of a string oli tubing 29 being screwed into the upper end of the barrel.

Secured to the lower end of chamber 2l, byr

means of coupling Sli, is a downwardly extending 40' cylindrical tube 3l which, at its lower extremity is coupled to an end section 32- providedv with a closure `cap 33. A solid abutment plug 3d is screwed into the lower end of tube 3l and limits the downward movement of a cylindrical tube 35 which has a sliding flt within tube 3i. Tubes 3l and 35 have radial openings 36 and 3l which lie in the same plane whenthe lower end of tube 35 is on abutment 34. Tube'has a relieved portion 3B extending above and below the plane of openings 3l, so that', vwhether or not openings 38 and 3l are in register, fluid may enter openings 36 and pass through openings 31 to the interior of tube 35. i i

The upper end of tube 35 is coupled to the lower extremity of a tube 39 which is slidably guided in a central opening in a spider 4|! fixed in chamber 2|, the spider having eccentrically arranged through-openings as at 4|. Tube 39 is connected at its upper end to the lower end of a tube 42 by means of a coupling 43. A tubular float 44, here shown as being of cork, embraces tube 42 with its lower end in abutment with coupling 43. An abutment nut 45 is screwed on the upper end of tube 42 as is also a bushing 46 which is slidably guided in the centralopening of a spider 41, the spider having an eccentrically arranged series of through-openings as at 48.

Secured in the upper end of chamber 2| is a tting or plug 49 which has formed therein a cavity 59. A tube 52 is threaded in an eccentric port communicating with cavity 59 of tting 49 and extends downwardly through an opening 48 of spider 41 and an opening 4| of spider 40 to a point adjacent the bottom of chamber 2|'. Fitting 49 has eccentrically disposed through-openings as at 53 and has a top port communicating with cavity 59 in which is threaded the lower extremity of a tube 54 which extends upwardly through plug 21 and has lock nuts 55 threaded on its upper extremity, a packing gasket 56 being interposed between the lower nut and the top 13| are immersed only in oil. With the parts in of the plug.

Packer 24 is disposed ordinarily about thirty feet from the bottom of the well and thus blocks rise of the oil under bottom hole pressure beyond this point. Due to the maintenance of this pressure, water is prevented from rising in the casing so that chamber 2| and its downward extension the position shown, oil at bottom hole pressure will pass through openings 36 and 31 and upwardly through the tubing system 35, 39 and 42 to overiiow into chamber 2|. When the chamber 2| is substantially full, iioat 44 will lift carrying tube 35 therewith and thus bring a full circumferential portion of tube 35 in closing relation to vopenings 36, so that further access of oil to chamber 2| is prevented. Gas entrained in the oil in chamber 2| escapes through the openings as at 53 in plug 49, through the upper end of chamber 2|, pipe section 22, packer 24 and pipe section to escape through opening 25 to the yinterior of the casing above the packer and thence to the top of the casing, so that the oil in chamber 2| assumes substantially atmospheric pressure. Upon operation of the pump, oil is drawn from the bottom of chamber 2| through tube 52, cavity 50 and tube 54 to the inlet end of the pump.

Assuming bottom hole pressure to be around twelve hundred pounds to the square inch, it will be evident that the static pressure at the lower extremity of a column ofI any ordinary height in tubing 22 will be less and that, accordingly, the pump would be unable to operate as such in view of the fact that the excess bottom pressure would hold the standing and travelling valves unseated in 'any ordinary installation. This diiculty is entirely obviated by the provision of the pressure reducing, gas separation chamber 2|, as will be understood. Since the pressure in chamber 2| is substantially atmospheric, the pump must ,of course, be located near enough to the chamber so as to have proper lift. It will be understood that as the pump evacuates chamber 2l, float 44 will fall and the valve 3|-35 will again enable oil to ow into the 75;: chamber. Such ow is permitted before chamber 2| is entirely empty, so that the pump can never draw directly from the well bottom so as to disturb the underlying formations.

At the commencement of pumping, fluid above the packer will be first Withdrawn, such fluid settling into chamber 2| through opening 25 and the intermediate connections.

By maintaining bottom hole pressure and pumping the oil that rises to the top of the water, a slower encroachment of water in the oil sand results, because the uid level being maintained constant by means of the packer, the rising oil pushes back the water, giving the well longer life and greater recovery of oil than is now possible. The new system, eliminating the pumping of water, enables smaller tubing to be used and reduces the cost of pumping. It substantially eliminates treatment of emulsied oil and water and the problem of water disposal.

To refer to Figures '7 and 8, reference numeral 69 designates the lower portion of a well casing, reference numeral 6| a packer, preferably disposed about thirty feet from the well bottom, and reference numeral 62 the lower portion of a tube line. Reference numeral 63 designates a pump barrel secured at the lower end of the line and reference numeral 64 a reducing valve secured to the lower end of the pump through a connector 65, or it may be directly connected thereto.

The reducing valve comprises a lower casing portion 66 having formed therein an inlet cavity 61 and an outlet cavity 68 with a partition 69 therebetween. Cavity 61 has a central bottom opening in which is threaded a plug 10 which has an axial bore 1| and an upper annular recess 12. A central opening in partition 69 has a valve seat 13 threaded therein and the top wall 14 of cavity 68 has a central opening in which is threaded a bushing y15. Portion 66 has a top iiange to which is bolted the lower flange of a casing portion 16, a diaphragm 11 being clamped between the flanges. Portion 16 has a lower central cylindrical cavity 18 which has an upwardly reduced portion 19. Above the reduced portion 19, member 16 is annularly recessed and threaded to receive the threaded end of a plug 80, a diaphragm 8| being clamped between the lower end of the plug and the underlying shoulder of member 16. Plug 8&1 has a downwardly opening cylindrical cavity 82 of the same diameter as the reduced cavity portion 19. Plug 80 has a counterbore 83 running from its exterior into cavity 82. A bore 84 extends downwardly from the top of plug 80 through member 15 and intomember 66 to the outlet cavity 68, so that the latter is placed in communication with the lower end of the pump barrel through connector 65.

A rigid pedestal 85 extends in transmitting relation between diaphragms 11 and 8| and is freely slidable in the isolated cavity 18. A block 86 below diaphragm 11 has a central recess receiving the upper extremity of a valve stem 81 slidable in bushing 15 and, at its lower extremity, in bore 1|. Stem 81 has rigidly xed thereon a valve disc 88 underlying seat 13 for cooperation therewith, the valve disc being yieldingly urged toward the seat by means of a compression spring 89 disposed between the disc and the bottom of recess 12. Cavity 61 has an inlet opening 90. Cavity 68 is in communication with the space beneath diaphragm 11 through an opening 9|.

To complete the assembly counterbore 83 is connected by means of a length of small tubing 92 with tubing line 62 immediately above pump barrel 53. Ifdesired, a strainer or the like 93 may be secured to the lower end ot valve t4.

In the initial position of parts, valve disc 88 is held seated by spring 39, diaphragm Il being unflexed. With the valve disposed in the well bottom below the packer, bottom hole pressure wil be exerted cn the small bottom area ofthe valve discBS. The static pressure in the bottom of the string of tubing and communicated to the top of diaphragm Si through the conduit 92 will overcome the pressure on the bottom of the valve disc and cause it to open slightly and permit oilat reduced pressure to enter cavity 63 and to pass up to the bottom of the pump through passage 84. The reduced pressure is communicated to the bottom of diaphragm il through opening Qi. Due to the'fact that the eiective area or" diaphragm SI is less than the effective ,area of diaphragm ll', it follows that disc 88 can only remain unseated so long as there is a predominant pressure on diaphragm 8i. When this pressure differential exists it, oir" course, follows that the static pressure at the lower end or" the tubing string is greater than the pressure in chamber S3 and with this condition present the pump'can function properly. The differential is maintained automatically regardless of fluctuations of static presure in the bottom of the tubing string caused by varying conditions of gas release in the oil column.

As here shown, the pump is disposed below the packer in order to favor installation of conduit Q2, which must extend from just above the pump outlet to the pressure reducing valve which is below the pump intake. Otherwise, it will be understood that the spacing of parts need only be such with relation to the diaphragm areas as to enable proper differential pressure to be obtained.

The reducing valve Sil of Figure 9 may be substituted for the valve E4 and secured in place of the latter in the lowerendol the connection 55. A lower casingpart has formed therein an inlet cavity with inlet opening @t and an outlet cavity Si?, a connecting port between the two being controlled by a spring-pressed valve disc S8. A diaphragm 99 is clamped between the lower casing part and an upper casing part which houses a compression spring lli-i, whose compression is adjustable by means of a hollow screw Eil which is isolated by means of a solid plug IBE. A passage U33 leads upwardly from cavity @il to the interior of connection 55.

Diaphragm 99 is influenced by the reduced bottom hole pressure in cavity ii'l, this pressure having access to the bottom of the diaphragm through an opening lilll and being dependent upon the adjustment of the spring lut. With a bottom hole pressure of twelve hundred pounds per square inch, for example, the spring may be adjusted so that oil will reach the pump at a pressure of say six hundred pounds, assuming that this latter pressure is less than the static pressure at the bottom of the tubing string.

While I have stated above that the packer is preferably placed about thirty feet above the top of the oil producing sand, this disposition will depend on a number of factors peculiar to the oil well in question. It may be said, however, that under ordinary circumstances the packer will be placed in the casing from around thirty feet to around three hundred feet above the top of the oil producing sand.

It is the intention in lowering the devices of the present invention with the packer and pumping equipment, that the tubing will be filled with uid, either oil or water, so that a working condition will obtain when the apparatus is nally set in the well. In the use of the reducing valves the pump may be set quite a distance above the packer, but when the separation chamber is used and the oil brought to approximately atmospheric pressure, the chamber should be positioned near the packer and the pump located adjacent the chamber.

It will be understood that the disclosed means for carrying out the invention are subject to variation without departure from the invention. The described examples are merely illustrative of practical devices which may be used. Accordingly, I do not limit myself except-as in the following claims.

I claim:

1. Apparatus for taking oil from a water drive well comprising a pump and tubingline in the well, a packer adjacent the well bottom for maintaining bottom hole pressure, and means connecting the pump inlet 'with the well below the packer and including a pressure reducing chamber wherein oil admitted through a chamber inlet is reduced to a pressure below that which exists at the bottom of a column of oil in' said tubing above said pump, a valve controlling said chamber inlet, and a float in said chamber controlling said valve.

2. Apparatus for taking oil from a water drive well comprising a pump and tubing line in the well, a packer adjacent the well bottom for maintaining bottom hole pressure, and means including a chamber connecting the pump inlet with the well below the packer, said chamber having an escape opening for gas separating from oil admitted to said chamber, oil in said chamber assuming a pressure less than that which exists at thel bottom of a column of oil in said tubing above said pump.

3. Apparatus for taking oil from a water drive well comprising a pump and tubing line in the well, a `packer adjacent the well bottom kfor maintainingbottomhole pressure, and means including a chamber connecting the pump inlet with the well below the packer, said chamber having a top float controlled inlet and a bottom outlet and having an escape opening for gas separating from oil admitted to said chamber, oil in said chamber assuming a pressure less than that which exists at the bottom of a column of oil in said tubing above said pump.

4. Apparatus for taking oil from a water drive well comprising a pump and tubing line in the well, a packer adjacent the well bottom for maintaining bottom hole pressure, and a chamber below the packer in connection with the inlet end of the pump, a vertically slidable oat-controlled tube constituting inlet means for said chamber and having its upper discharge end in the top portion of said chamber, said tube constituting the movable portion of a valve which is open when the tube is in a lower position and closed when the tube is in an upper position, and a withdrawal tube leading to the pump inlet from a point near the bottom of said chamber, said chamber having an escape opening for gas sepawell, a packer adjacent the well bottom for maintaining bottom hole pressure, and means connecting the inlet end of the pump with the well below said packer and including pressure reducing valve whereby pressure at the inlet end of the pump is reduced below that which exists at the bottom of a column of oil in said tubing line, said valve being controlled in dependence upon the differential between the reduced pressure of the oil delivered thereby and the static pressure at the bottom of the tubing line above said pump.

6. Apparatus according to claims wherein for the control of the valve the latter includes a pair of opposed diaphragms of different effective areas, that with the larger area being directly affected by the reduced pressure of the oil delivered by the valve and the other being directly aiected by the pressure at the bottom of the tubing line.

'1. Apparatus for taking oil from a water drive well comprising a pump and tubing line in the well, the pump being at the lower end of the tubing line, a packer adjacent the well bottom for confining the natural rise in the well and maintaining bottom hole pressure, and means connecting the inlet end of the pump with the well below said packer and including a manually adjustable spring loaded pressure reducing valve whereby pressure at the inlet end of the pump is reduced below that which exists at the bottom of a column of oil in said tubing line above said pump.

8. Apparatus for taking oil from a water drive well comprising a pump and tubing line in the well, the pump being at the lower end of the tubing line, means blocking the well adjacent its bottom to confine the natural rise in the well and maintain bottom hole pressure, and means for connecting the pumpy intake with the well below the packer, said connecting means including means for effecting reduction of pressure below that existing at the pump outlet when a column of oil is in said tubing line above said pump.

9. Apparatus for taking oil from a water drive well comprising a pump and tubing line in the well, the pump being at the lower end of the tubing line, means blocking the well adjacent its bottom to conne the natural rise in the well and maintain bottom hole pressure, and means for connecting the pump intake with the well below the packer, said connecting means including means for eiecting intermittent supply to the pump intake and reduction of pressure below that existing at the pump outlet when a column of oil is in said tubing line above said pump.

CHARLES LEVIN ADAMS TODD. 

